title: [Research on sludge toxicity caused by DMF biodegradation and toxicity spatial distribution in sludge flocs].
abstract: The aerobic sequencing batch activated sludge system (SBR) was used to remove the toxic and refractory organic pollutant, N,N-dimethylformamide (DMF). The formation property and spatial distribution of the organic toxicity in sludge were studied. The operation parameters were controlled as follows: influent COD was about 300 mg x L(-1), every DMF concentration phase lasted 30 d(40 mg x L(-1), 80 mg x L(-1), 120 mg x L(-1)), the SBR cycle lasted 12 h, and DO was 2.0-3.0 mg x L(-1). The results showed that the sludge toxicity increased in the beginning and then decreased to a steady range at each DMF concentration phase; there was a positive correlation between the sludge toxicity and the initial DMF concentration; most of the sludge organic toxicity was caused by DMF biodegradation and existed in the inner extracellular polymeric substances (EPS) and intracellular section of sludge flocs.
authors.affiliation: College of Resources and Environmental Engineering, East China University of Science and Technology, Shanghai 200237, China. huyuanyuan_good@163.com
authors.forename: Yuan-Yuan
authors.initials: YY
authors.lastname: Hu
authors.forename: Na
authors.initials: N
authors.lastname: Yang
authors.forename: Yi
authors.initials: Y
authors.lastname: Ding
authors.forename: Wen-Lu
authors.initials: WL
authors.lastname: Xu
authors.forename: Xiu-Rong
authors.initials: XR
authors.lastname: Chen
authors.forename: Qi-Feng
authors.initials: QF
authors.lastname: Ai
authors.forename: Shan-Jia
authors.initials: SJ
authors.lastname: Chen
authors.forename: Li-Peng
authors.initials: LP
authors.lastname: Wang
authors.forename: Hua
authors.initials: H
authors.lastname: Huang
mesh_terms: D000332:Aerobiosis; D001673:Biodegradation, Environmental; D019149:Bioreactors / Q000382:microbiology*; D004126:Dimethylformamide / Q000032:analysis / Q000378:metabolism / Q000633:toxicity*; D012722:Sewage / Q000737:chemistry*; D062206:Spatial Analysis; D014865:Waste Disposal, Fluid / Q000379:methods*
chemical_list: D012722:Sewage; D004126:Dimethylformamide